QI want to add items to an order I placed earlier

While an order is "Waiting For Processing", you can add items you put in your cart with "Add from Cart" in "Change Order Items" in Order History. After we start processing the order, place a new order and select "Combined Delivery" under "Delivery Option & Delivery Fee" at checkout, and we will ship it together with your earlier order (available when the shipping address is the same and the earlier order has not shipped yet).